What does the alpha and beta versions of the software mean?

Beta, which is commonly thought of as "testing". In a broad sense, there are three traditional names for testing: Alpha (Alpha), beta (beta), and gamma (gamma), which identify the stages and scopes of testing.
Alpha refers to the beta, which is now called CB, the development team internal test version or Limited User experience test version.
Beta refers to public testing, which is a beta version that is exposed to all users.
and made some changes to become the official release of the candidate version (now called Rc-release candidate), called Gamma.